Acrylamide polymers having electrolytic groups such as phosphorus acid groups (for instance, a (poly)phosphoric group, a (poly)phosphonic group), or a sulfonate group are useful for wide varieties of applications as conductive materials, paper modifiers, hygiene materials, agricultural materials, etc. Among them, acrylamide polymers having phosphorus acid groups as electrolytic groups are insoluble in water and have excellent oxidation resistance and flame retardance despite hydrophilicity. Accordingly, they are useful particularly for various applications such as conductive resins, antistatic agents, paper modifiers and coating agents. For instance, JP10-251990A discloses a paper-making additive comprising phosphoric-group-containing poly(meth)acrylamide derivatives.
However, when electrolytic-group-containing acrylamide polymers are used as solid polymer electrolytes, they are desired to have higher conductivity. To improve the conductivity of the electrolytic-group-containing acrylamide polymers, it is effective to increase their electrolytic group densities, for instance. However, the phosphoric-group-containing poly(meth)acrylamide derivatives of JP10-251990A, which are obtained by copolymerizing(meth)acrylamide and phosphoric-group-containing, unsaturated monomers, fail to have a satisfactory level of electrolytic group densities.
Thus, the applicant proposed a sulfonate-group-containing acrylamide polymer obtained by introducing a (poly)phosphonic group into a polymer constituted by a unit represented by the following general formula (21):
wherein R23 is a hydrogen group or a methyl group, R24 and R25 are a hydrogen group or an alkyl group having 1-3 carbon atoms, R26 is an alkylene group having 1-3 carbon atoms, M2 is a hydrogen group, an alkali metal, an ammonium ion or an amine group (JP2004-331810A). However, this polymer differs from those obtained by introducing a phosphorus acid group into sulfonate-group-containing (meth)acrylamide monomers, and polymerizing the resultant derivatives. Accordingly, the polymer of JP2004-331810A fails to have a satisfactory level of electrolytic group density.